Electron-discharge device



Nov. 8, 1927. 1,647,996

F. L. HUNTER, JR., ET AL ELECTRON DISCHARGE DEVICE Filed Jan. 17. 1924 m V/iN TOR Frederick L. HunTer,Jn SylvesTer W. Crowley Patented Nov. 8, 1927.

UNITED STATES PATENT eFr cE.

FREDERICK L. HUNTER, JR., F TOWACO, AND SYLVESTER W. CROWLEY, 0F WEE- HAWKEN, NEW JERSEY, ASSIGNORS TO DE FOB-EST RADIO TELEPHONE & TELE- GRAPH 00., OF JERSEY CITY, NEW JERSEY, A CORPORATION OF DELAWARE.

ELECTRON-DISCHARGE DEVICE.

Application filed January 17. 1924. Serial No. 686,827.

This invention relates to electron discharge devices, and particularly to such devices as are used in connection-with telephonic and telegraphic apparatus.

In electron discharge devices, or tubes as heretofore manufactured, the plate and grid.- have been relatively large, and the supporting wires and leads have been comparatively long. As a result of this struc- 1o ture as employed in the prior art, considerable capacity results, which is more than enough to make the tube oscillate when operating in a radio circuit. In the type of tube illustrated herein, and covered more generally in our prior application, Serial Number 680,850, filed December 15, 1923, the

plate and grid are relatively small, and the supporting wires and leads are comparatively short. We have found, as a consequence, that the capacity of the tube with the usual arrangement of parts is insufficient to make it oscillate at all times desired, and particularly is such that the tube does not oscillate in a tightly coupled circuit.

The objects of the invention are to provide means in an electron discharge device for increasing its capacity without enlarging or altering the plate and grid structure; to provide means which may be adjusted to meet the requirements of the particular type of tube; to obtain the capacity required Within the tube so as to enable the tube to be interchangeable with other kinds of tubes; to enable the capacity to be readily obtained :55 by novel arrangement of parts; to secure simplicity of construction and operation, and to obtain other advantages and results as may be brought out in the following description.

Referring to the accompanying drawing in which like numerals of reference indicate similar parts throughout the several views;

Figure l is an elevation of an electron discharge device constructed in accordance with 45 our invention and showing part of the bulb broken away for disclosing the interior construction;

Figure 2 is a vertical central section longitudinally of the bulb and transversely of the plate, grid and filament; and

Figure 3 is a horizontal sectional view as upon line 33 of Figure 2.

In the specific embodiment of the invention illustrated in said drawing, the refer ence numeral 1 indicates the usual base, and numeral 2 represents the usual bulb, cemented together in axial alignment and constituting the exterior portion of the usual electron discharge device or tube. Within the bulb, and also extending axially or longitudinally thereof, is a stem 3 supportlng at its end in transverse relation thereto, a cylindrically shaped plate 4 through which extend the grid 5 and filament 6. Attention is to be directed to the fact that the plate and grid are small as compared to the usual plate and grid, and therefore, as usually employed have no very great capacity, it being found that the actual capacity in the usual arrangement is insufficient to make the tube oscillate in all cases where it should.

We have discovered that it is possible and practical to make a tube oscillate which otherwise has insufficient plate-grid capacity for that purpose, by arranging the plate and grid eccentric to each other. While the device will have insufiicient capacity to cause it to oscillate when the grid and plate are arranged as usual in concentric position, We find that positioning the grid closer to the plate along one side than at its other side, will increase the capacity all that is necessary. Of course the relative positions of grid and plate can be adjusted to give more or less capacity, more capacity being ob mined as the grid and plate are made more eccentric or brought closer together at one side, and less capacity being obtained as the grid and plate are brought nearer to a concentric condition. The capacity obtained by this eccentricity of grid and plate will not only make up for the lack of capacity between plate and grid, but will make up for loss of capacity resulting from the shortening of the usual supporting wires for the plate and grid. By this means we provide increased capacity within the tube itself, and thus enable the tube to properly oscillate and be substituted in circuits where other types of tubes have heretofore been used. Preferably the filament 6 is arranged substantially concentric with respect to the grid, although this may be varied as found desirable.

Obviously detail changes and modifications may be made in the manufacture and use of our improved electron discharge device, and we do not wish to be understood as limiting ourselves to the exact structure shown except as set forth in the following 5 claims when construed in the light of the prior art.

Having thus described our invention, we claim 1. An electron discharge device having a cathode, a substantially cylindrical plate and 1 grid arranged eccentncally to each other.

2. An electron discharge device having a plate, grid and filament, said grid and filament being concentric with respect to each other but eccentric with respect to said plate.

FREDERICK L. HUNTER, J R. SYLVESTER W. CROWLEY. 

